Four US soldiers killed in Afghan 'insider' attack

Four U.S. troops fighting with the NATO-led alliance were killed in another suspected "insider" attack in southern Afghanistan. NBC's Atia Abawi reports.

By NBC News staff and wire services

Updated at 12:05 p.m. ET: Four U.S. soldiers fighting with the NATO-led alliance were killed in an apparent insider shooting in southern Afghanistan on Sunday, the Pentagon confirmed.

A Pentagon spokesman did not have further details, including which branch of services the Americans belonged to, Reuters reported.

The shooting took place in Zabol, a southern province where U.S. forces are based, and came a day after two British soldiers were shot dead by an Afghan policeman while returning from a patrol in southern Helmand province — a stronghold of the Taliban-led insurgency.

Local authorities also told NBC News that the four killed were Americans.

An International Security Assistance Force (ISAF) statement described the incident as "an insider attack suspected to involve members of the Afghan police."

One attacker who was wearing an Afghan National Police uniform (ANP) was also killed in the fighting, a source told Reuters.

At least 51 foreign military personnel have been killed in "insider" attacks this year, attacks which have put a heavy strain on trust between the coalition and Afghanistan as they move towards handing security responsibility to Afghan forces by the end of 2014.

The rise in such attacks has led to the training of new recruits to the Afghan army and police being suspended.

The Taliban indicates that deadly attacks on U.S. personnel in Afghanistan were in response to an anti-Islam video. NBC's Atia Abawi reports.

With foreign combat troops withdrawing from the increasingly unpopular and expensive war, the enormous cultural divide that still separates Afghans and their allies after 11 years of conflict has become more of a concern than ever.

The NATO-led coalition and its Afghan counterparts have created a special Joint Casualties Assessment Team to investigate every attack, which number at least 37 this year.

In more than half of cases, attackers are either killed or escape and the motive never emerges, making it more difficult for the coalition to stem the surge.

Adding to the toll of coalition deaths caused by insider attacks over the weekend, two were killed and nine wounded in Friday's attack on Camp Bastion, one of the worst attacks on a NATO-operated base all year.

Six Harrier jets were destroyed and two were significantly damaged in the raid on the camp airfield, carried out by 15 insurgents wearing U.S. Army uniforms and split between three teams, a NATO statement said on Sunday.

Three refueling stations were destroyed and six aircraft hangars were damaged. Britain's Prince Harry was at Camp Bastion at the time of Friday's attack, but was unharmed.

US forces based at Kabul International Airport in Afghanistan take part in a memorial service marking the 11th anniversary of the September 11 attacks. NBCNews.com's Dara Brown reports.

All but one of the attackers were killed, with the remaining fighter taken into custody by coalition forces.

ISAF said the attack was "well-coordinated". A statement said: "The insurgents, organized into three teams, penetrated at one point of the perimeter fence. The insurgents appeared to be well equipped, trained and rehearsed. Dressed in U.S. Army uniforms and armed with automatic rifles, rocket propelled grenade launchers and suicide vests, the insurgents attacked coalition fixed and rotary wing aircraft parked on the flight line, aircraft hangars and other buildings."

With foreign combat troops withdrawing from the unpopular and expensive war by the end of 2014, the enormous cultural divide that still separates Afghans and their allies after 11 years of war has become more of a concern than ever.

The NATO-led coalition and its Afghan counterparts have created a special Joint Casualties Assessment Team to investigate every attack.

In more than half of the cases, attackers are either killed or escape and the motive for the incident never emerges, making it more difficult for the coalition to stem the surge in incidents.